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1 // Copyright 2014 The Chromium Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4 
5 #include <stdio.h>
6 #include <stdlib.h>
7 #include <algorithm>   // for min()
8 
9 #include "base/atomicops.h"
10 #include "testing/gtest/include/gtest/gtest.h"
11 
12 // Number of bits in a size_t.
13 static const int kSizeBits = 8 * sizeof(size_t);
14 // The maximum size of a size_t.
15 static const size_t kMaxSize = ~static_cast<size_t>(0);
16 // Maximum positive size of a size_t if it were signed.
17 static const size_t kMaxSignedSize = ((size_t(1) << (kSizeBits-1)) - 1);
18 // An allocation size which is not too big to be reasonable.
19 static const size_t kNotTooBig = 100000;
20 // An allocation size which is just too big.
21 static const size_t kTooBig = ~static_cast<size_t>(0);
22 
23 namespace {
24 
25 using std::min;
26 
27 // Fill a buffer of the specified size with a predetermined pattern
Fill(unsigned char * buffer,int n)28 static void Fill(unsigned char* buffer, int n) {
29   for (int i = 0; i < n; i++) {
30     buffer[i] = (i & 0xff);
31   }
32 }
33 
34 // Check that the specified buffer has the predetermined pattern
35 // generated by Fill()
Valid(unsigned char * buffer,int n)36 static bool Valid(unsigned char* buffer, int n) {
37   for (int i = 0; i < n; i++) {
38     if (buffer[i] != (i & 0xff)) {
39       return false;
40     }
41   }
42   return true;
43 }
44 
45 // Check that a buffer is completely zeroed.
IsZeroed(unsigned char * buffer,int n)46 static bool IsZeroed(unsigned char* buffer, int n) {
47   for (int i = 0; i < n; i++) {
48     if (buffer[i] != 0) {
49       return false;
50     }
51   }
52   return true;
53 }
54 
55 // Check alignment
CheckAlignment(void * p,int align)56 static void CheckAlignment(void* p, int align) {
57   EXPECT_EQ(0, reinterpret_cast<uintptr_t>(p) & (align-1));
58 }
59 
60 // Return the next interesting size/delta to check.  Returns -1 if no more.
NextSize(int size)61 static int NextSize(int size) {
62   if (size < 100)
63     return size+1;
64 
65   if (size < 100000) {
66     // Find next power of two
67     int power = 1;
68     while (power < size)
69       power <<= 1;
70 
71     // Yield (power-1, power, power+1)
72     if (size < power-1)
73       return power-1;
74 
75     if (size == power-1)
76       return power;
77 
78     assert(size == power);
79     return power+1;
80   } else {
81     return -1;
82   }
83 }
84 
85 template <class AtomicType>
TestAtomicIncrement()86 static void TestAtomicIncrement() {
87   // For now, we just test single threaded execution
88 
89   // use a guard value to make sure the NoBarrier_AtomicIncrement doesn't go
90   // outside the expected address bounds.  This is in particular to
91   // test that some future change to the asm code doesn't cause the
92   // 32-bit NoBarrier_AtomicIncrement to do the wrong thing on 64-bit machines.
93   struct {
94     AtomicType prev_word;
95     AtomicType count;
96     AtomicType next_word;
97   } s;
98 
99   AtomicType prev_word_value, next_word_value;
100   memset(&prev_word_value, 0xFF, sizeof(AtomicType));
101   memset(&next_word_value, 0xEE, sizeof(AtomicType));
102 
103   s.prev_word = prev_word_value;
104   s.count = 0;
105   s.next_word = next_word_value;
106 
107   EXPECT_EQ(base::subtle::NoBarrier_AtomicIncrement(&s.count, 1), 1);
108   EXPECT_EQ(s.count, 1);
109   EXPECT_EQ(s.prev_word, prev_word_value);
110   EXPECT_EQ(s.next_word, next_word_value);
111 
112   EXPECT_EQ(base::subtle::NoBarrier_AtomicIncrement(&s.count, 2), 3);
113   EXPECT_EQ(s.count, 3);
114   EXPECT_EQ(s.prev_word, prev_word_value);
115   EXPECT_EQ(s.next_word, next_word_value);
116 
117   EXPECT_EQ(base::subtle::NoBarrier_AtomicIncrement(&s.count, 3), 6);
118   EXPECT_EQ(s.count, 6);
119   EXPECT_EQ(s.prev_word, prev_word_value);
120   EXPECT_EQ(s.next_word, next_word_value);
121 
122   EXPECT_EQ(base::subtle::NoBarrier_AtomicIncrement(&s.count, -3), 3);
123   EXPECT_EQ(s.count, 3);
124   EXPECT_EQ(s.prev_word, prev_word_value);
125   EXPECT_EQ(s.next_word, next_word_value);
126 
127   EXPECT_EQ(base::subtle::NoBarrier_AtomicIncrement(&s.count, -2), 1);
128   EXPECT_EQ(s.count, 1);
129   EXPECT_EQ(s.prev_word, prev_word_value);
130   EXPECT_EQ(s.next_word, next_word_value);
131 
132   EXPECT_EQ(base::subtle::NoBarrier_AtomicIncrement(&s.count, -1), 0);
133   EXPECT_EQ(s.count, 0);
134   EXPECT_EQ(s.prev_word, prev_word_value);
135   EXPECT_EQ(s.next_word, next_word_value);
136 
137   EXPECT_EQ(base::subtle::NoBarrier_AtomicIncrement(&s.count, -1), -1);
138   EXPECT_EQ(s.count, -1);
139   EXPECT_EQ(s.prev_word, prev_word_value);
140   EXPECT_EQ(s.next_word, next_word_value);
141 
142   EXPECT_EQ(base::subtle::NoBarrier_AtomicIncrement(&s.count, -4), -5);
143   EXPECT_EQ(s.count, -5);
144   EXPECT_EQ(s.prev_word, prev_word_value);
145   EXPECT_EQ(s.next_word, next_word_value);
146 
147   EXPECT_EQ(base::subtle::NoBarrier_AtomicIncrement(&s.count, 5), 0);
148   EXPECT_EQ(s.count, 0);
149   EXPECT_EQ(s.prev_word, prev_word_value);
150   EXPECT_EQ(s.next_word, next_word_value);
151 }
152 
153 
154 #define NUM_BITS(T) (sizeof(T) * 8)
155 
156 
157 template <class AtomicType>
TestCompareAndSwap()158 static void TestCompareAndSwap() {
159   AtomicType value = 0;
160   AtomicType prev = base::subtle::NoBarrier_CompareAndSwap(&value, 0, 1);
161   EXPECT_EQ(1, value);
162   EXPECT_EQ(0, prev);
163 
164   // Use test value that has non-zero bits in both halves, more for testing
165   // 64-bit implementation on 32-bit platforms.
166   const AtomicType k_test_val = (static_cast<uint64_t>(1) <<
167                                  (NUM_BITS(AtomicType) - 2)) + 11;
168   value = k_test_val;
169   prev = base::subtle::NoBarrier_CompareAndSwap(&value, 0, 5);
170   EXPECT_EQ(k_test_val, value);
171   EXPECT_EQ(k_test_val, prev);
172 
173   value = k_test_val;
174   prev = base::subtle::NoBarrier_CompareAndSwap(&value, k_test_val, 5);
175   EXPECT_EQ(5, value);
176   EXPECT_EQ(k_test_val, prev);
177 }
178 
179 
180 template <class AtomicType>
TestAtomicExchange()181 static void TestAtomicExchange() {
182   AtomicType value = 0;
183   AtomicType new_value = base::subtle::NoBarrier_AtomicExchange(&value, 1);
184   EXPECT_EQ(1, value);
185   EXPECT_EQ(0, new_value);
186 
187   // Use test value that has non-zero bits in both halves, more for testing
188   // 64-bit implementation on 32-bit platforms.
189   const AtomicType k_test_val = (static_cast<uint64_t>(1) <<
190                                  (NUM_BITS(AtomicType) - 2)) + 11;
191   value = k_test_val;
192   new_value = base::subtle::NoBarrier_AtomicExchange(&value, k_test_val);
193   EXPECT_EQ(k_test_val, value);
194   EXPECT_EQ(k_test_val, new_value);
195 
196   value = k_test_val;
197   new_value = base::subtle::NoBarrier_AtomicExchange(&value, 5);
198   EXPECT_EQ(5, value);
199   EXPECT_EQ(k_test_val, new_value);
200 }
201 
202 
203 template <class AtomicType>
TestAtomicIncrementBounds()204 static void TestAtomicIncrementBounds() {
205   // Test increment at the half-width boundary of the atomic type.
206   // It is primarily for testing at the 32-bit boundary for 64-bit atomic type.
207   AtomicType test_val = static_cast<uint64_t>(1) << (NUM_BITS(AtomicType) / 2);
208   AtomicType value = test_val - 1;
209   AtomicType new_value = base::subtle::NoBarrier_AtomicIncrement(&value, 1);
210   EXPECT_EQ(test_val, value);
211   EXPECT_EQ(value, new_value);
212 
213   base::subtle::NoBarrier_AtomicIncrement(&value, -1);
214   EXPECT_EQ(test_val - 1, value);
215 }
216 
217 // This is a simple sanity check that values are correct. Not testing
218 // atomicity
219 template <class AtomicType>
TestStore()220 static void TestStore() {
221   const AtomicType kVal1 = static_cast<AtomicType>(0xa5a5a5a5a5a5a5a5LL);
222   const AtomicType kVal2 = static_cast<AtomicType>(-1);
223 
224   AtomicType value;
225 
226   base::subtle::NoBarrier_Store(&value, kVal1);
227   EXPECT_EQ(kVal1, value);
228   base::subtle::NoBarrier_Store(&value, kVal2);
229   EXPECT_EQ(kVal2, value);
230 
231   base::subtle::Acquire_Store(&value, kVal1);
232   EXPECT_EQ(kVal1, value);
233   base::subtle::Acquire_Store(&value, kVal2);
234   EXPECT_EQ(kVal2, value);
235 
236   base::subtle::Release_Store(&value, kVal1);
237   EXPECT_EQ(kVal1, value);
238   base::subtle::Release_Store(&value, kVal2);
239   EXPECT_EQ(kVal2, value);
240 }
241 
242 // This is a simple sanity check that values are correct. Not testing
243 // atomicity
244 template <class AtomicType>
TestLoad()245 static void TestLoad() {
246   const AtomicType kVal1 = static_cast<AtomicType>(0xa5a5a5a5a5a5a5a5LL);
247   const AtomicType kVal2 = static_cast<AtomicType>(-1);
248 
249   AtomicType value;
250 
251   value = kVal1;
252   EXPECT_EQ(kVal1, base::subtle::NoBarrier_Load(&value));
253   value = kVal2;
254   EXPECT_EQ(kVal2, base::subtle::NoBarrier_Load(&value));
255 
256   value = kVal1;
257   EXPECT_EQ(kVal1, base::subtle::Acquire_Load(&value));
258   value = kVal2;
259   EXPECT_EQ(kVal2, base::subtle::Acquire_Load(&value));
260 
261   value = kVal1;
262   EXPECT_EQ(kVal1, base::subtle::Release_Load(&value));
263   value = kVal2;
264   EXPECT_EQ(kVal2, base::subtle::Release_Load(&value));
265 }
266 
267 template <class AtomicType>
TestAtomicOps()268 static void TestAtomicOps() {
269   TestCompareAndSwap<AtomicType>();
270   TestAtomicExchange<AtomicType>();
271   TestAtomicIncrementBounds<AtomicType>();
272   TestStore<AtomicType>();
273   TestLoad<AtomicType>();
274 }
275 
TestCalloc(size_t n,size_t s,bool ok)276 static void TestCalloc(size_t n, size_t s, bool ok) {
277   char* p = reinterpret_cast<char*>(calloc(n, s));
278   if (!ok) {
279     EXPECT_EQ(NULL, p) << "calloc(n, s) should not succeed";
280   } else {
281     EXPECT_NE(reinterpret_cast<void*>(NULL), p) <<
282         "calloc(n, s) should succeed";
283     for (int i = 0; i < n*s; i++) {
284       EXPECT_EQ('\0', p[i]);
285     }
286     free(p);
287   }
288 }
289 
290 
291 // A global test counter for number of times the NewHandler is called.
292 static int news_handled = 0;
TestNewHandler()293 static void TestNewHandler() {
294   ++news_handled;
295   throw std::bad_alloc();
296 }
297 
298 // Because we compile without exceptions, we expect these will not throw.
TestOneNewWithoutExceptions(void * (* func)(size_t),bool should_throw)299 static void TestOneNewWithoutExceptions(void* (*func)(size_t),
300                                         bool should_throw) {
301   // success test
302   try {
303     void* ptr = (*func)(kNotTooBig);
304     EXPECT_NE(reinterpret_cast<void*>(NULL), ptr) <<
305         "allocation should not have failed.";
306   } catch(...) {
307     EXPECT_EQ(0, 1) << "allocation threw unexpected exception.";
308   }
309 
310   // failure test
311   try {
312     void* rv = (*func)(kTooBig);
313     EXPECT_EQ(NULL, rv);
314     EXPECT_FALSE(should_throw) << "allocation should have thrown.";
315   } catch(...) {
316     EXPECT_TRUE(should_throw) << "allocation threw unexpected exception.";
317   }
318 }
319 
TestNothrowNew(void * (* func)(size_t))320 static void TestNothrowNew(void* (*func)(size_t)) {
321   news_handled = 0;
322 
323   // test without new_handler:
324   std::new_handler saved_handler = std::set_new_handler(0);
325   TestOneNewWithoutExceptions(func, false);
326 
327   // test with new_handler:
328   std::set_new_handler(TestNewHandler);
329   TestOneNewWithoutExceptions(func, true);
330   EXPECT_EQ(news_handled, 1) << "nothrow new_handler was not called.";
331   std::set_new_handler(saved_handler);
332 }
333 
334 }  // namespace
335 
336 //-----------------------------------------------------------------------------
337 
TEST(Atomics,AtomicIncrementWord)338 TEST(Atomics, AtomicIncrementWord) {
339   TestAtomicIncrement<AtomicWord>();
340 }
341 
TEST(Atomics,AtomicIncrement32)342 TEST(Atomics, AtomicIncrement32) {
343   TestAtomicIncrement<Atomic32>();
344 }
345 
TEST(Atomics,AtomicOpsWord)346 TEST(Atomics, AtomicOpsWord) {
347   TestAtomicIncrement<AtomicWord>();
348 }
349 
TEST(Atomics,AtomicOps32)350 TEST(Atomics, AtomicOps32) {
351   TestAtomicIncrement<Atomic32>();
352 }
353 
TEST(Allocators,Malloc)354 TEST(Allocators, Malloc) {
355   // Try allocating data with a bunch of alignments and sizes
356   for (int size = 1; size < 1048576; size *= 2) {
357     unsigned char* ptr = reinterpret_cast<unsigned char*>(malloc(size));
358     CheckAlignment(ptr, 2);  // Should be 2 byte aligned
359     Fill(ptr, size);
360     EXPECT_TRUE(Valid(ptr, size));
361     free(ptr);
362   }
363 }
364 
TEST(Allocators,Calloc)365 TEST(Allocators, Calloc) {
366   TestCalloc(0, 0, true);
367   TestCalloc(0, 1, true);
368   TestCalloc(1, 1, true);
369   TestCalloc(1<<10, 0, true);
370   TestCalloc(1<<20, 0, true);
371   TestCalloc(0, 1<<10, true);
372   TestCalloc(0, 1<<20, true);
373   TestCalloc(1<<20, 2, true);
374   TestCalloc(2, 1<<20, true);
375   TestCalloc(1000, 1000, true);
376 
377   TestCalloc(kMaxSize, 2, false);
378   TestCalloc(2, kMaxSize, false);
379   TestCalloc(kMaxSize, kMaxSize, false);
380 
381   TestCalloc(kMaxSignedSize, 3, false);
382   TestCalloc(3, kMaxSignedSize, false);
383   TestCalloc(kMaxSignedSize, kMaxSignedSize, false);
384 }
385 
TEST(Allocators,New)386 TEST(Allocators, New) {
387   TestNothrowNew(&::operator new);
388   TestNothrowNew(&::operator new[]);
389 }
390 
391 // This makes sure that reallocing a small number of bytes in either
392 // direction doesn't cause us to allocate new memory.
TEST(Allocators,Realloc1)393 TEST(Allocators, Realloc1) {
394   int start_sizes[] = { 100, 1000, 10000, 100000 };
395   int deltas[] = { 1, -2, 4, -8, 16, -32, 64, -128 };
396 
397   for (int s = 0; s < sizeof(start_sizes)/sizeof(*start_sizes); ++s) {
398     void* p = malloc(start_sizes[s]);
399     ASSERT_TRUE(p);
400     // The larger the start-size, the larger the non-reallocing delta.
401     for (int d = 0; d < s*2; ++d) {
402       void* new_p = realloc(p, start_sizes[s] + deltas[d]);
403       ASSERT_EQ(p, new_p);  // realloc should not allocate new memory
404     }
405     // Test again, but this time reallocing smaller first.
406     for (int d = 0; d < s*2; ++d) {
407       void* new_p = realloc(p, start_sizes[s] - deltas[d]);
408       ASSERT_EQ(p, new_p);  // realloc should not allocate new memory
409     }
410     free(p);
411   }
412 }
413 
TEST(Allocators,Realloc2)414 TEST(Allocators, Realloc2) {
415   for (int src_size = 0; src_size >= 0; src_size = NextSize(src_size)) {
416     for (int dst_size = 0; dst_size >= 0; dst_size = NextSize(dst_size)) {
417       unsigned char* src = reinterpret_cast<unsigned char*>(malloc(src_size));
418       Fill(src, src_size);
419       unsigned char* dst =
420           reinterpret_cast<unsigned char*>(realloc(src, dst_size));
421       EXPECT_TRUE(Valid(dst, min(src_size, dst_size)));
422       Fill(dst, dst_size);
423       EXPECT_TRUE(Valid(dst, dst_size));
424       if (dst != NULL) free(dst);
425     }
426   }
427 
428   // Now make sure realloc works correctly even when we overflow the
429   // packed cache, so some entries are evicted from the cache.
430   // The cache has 2^12 entries, keyed by page number.
431   const int kNumEntries = 1 << 14;
432   int** p = reinterpret_cast<int**>(malloc(sizeof(*p) * kNumEntries));
433   int sum = 0;
434   for (int i = 0; i < kNumEntries; i++) {
435     // no page size is likely to be bigger than 8192?
436     p[i] = reinterpret_cast<int*>(malloc(8192));
437     p[i][1000] = i;              // use memory deep in the heart of p
438   }
439   for (int i = 0; i < kNumEntries; i++) {
440     p[i] = reinterpret_cast<int*>(realloc(p[i], 9000));
441   }
442   for (int i = 0; i < kNumEntries; i++) {
443     sum += p[i][1000];
444     free(p[i]);
445   }
446   EXPECT_EQ(kNumEntries/2 * (kNumEntries - 1), sum);  // assume kNE is even
447   free(p);
448 }
449 
TEST(Allocators,ReallocZero)450 TEST(Allocators, ReallocZero) {
451   // Test that realloc to zero does not return NULL.
452   for (int size = 0; size >= 0; size = NextSize(size)) {
453     char* ptr = reinterpret_cast<char*>(malloc(size));
454     EXPECT_NE(static_cast<char*>(NULL), ptr);
455     ptr = reinterpret_cast<char*>(realloc(ptr, 0));
456     EXPECT_NE(static_cast<char*>(NULL), ptr);
457     if (ptr)
458       free(ptr);
459   }
460 }
461 
462 #ifdef WIN32
463 // Test recalloc
TEST(Allocators,Recalloc)464 TEST(Allocators, Recalloc) {
465   for (int src_size = 0; src_size >= 0; src_size = NextSize(src_size)) {
466     for (int dst_size = 0; dst_size >= 0; dst_size = NextSize(dst_size)) {
467       unsigned char* src =
468           reinterpret_cast<unsigned char*>(_recalloc(NULL, 1, src_size));
469       EXPECT_TRUE(IsZeroed(src, src_size));
470       Fill(src, src_size);
471       unsigned char* dst =
472           reinterpret_cast<unsigned char*>(_recalloc(src, 1, dst_size));
473       EXPECT_TRUE(Valid(dst, min(src_size, dst_size)));
474       Fill(dst, dst_size);
475       EXPECT_TRUE(Valid(dst, dst_size));
476       if (dst != NULL)
477         free(dst);
478     }
479   }
480 }
481 
482 // Test windows specific _aligned_malloc() and _aligned_free() methods.
TEST(Allocators,AlignedMalloc)483 TEST(Allocators, AlignedMalloc) {
484   // Try allocating data with a bunch of alignments and sizes
485   static const int kTestAlignments[] = {8, 16, 256, 4096, 8192, 16384};
486   for (int size = 1; size > 0; size = NextSize(size)) {
487     for (int i = 0; i < ARRAYSIZE(kTestAlignments); ++i) {
488       unsigned char* ptr = static_cast<unsigned char*>(
489           _aligned_malloc(size, kTestAlignments[i]));
490       CheckAlignment(ptr, kTestAlignments[i]);
491       Fill(ptr, size);
492       EXPECT_TRUE(Valid(ptr, size));
493 
494       // Make a second allocation of the same size and alignment to prevent
495       // allocators from passing this test by accident.  Per jar, tcmalloc
496       // provides allocations for new (never before seen) sizes out of a thread
497       // local heap of a given "size class."  Each time the test requests a new
498       // size, it will usually get the first element of a span, which is a
499       // 4K aligned allocation.
500       unsigned char* ptr2 = static_cast<unsigned char*>(
501           _aligned_malloc(size, kTestAlignments[i]));
502       CheckAlignment(ptr2, kTestAlignments[i]);
503       Fill(ptr2, size);
504       EXPECT_TRUE(Valid(ptr2, size));
505 
506       // Should never happen, but sanity check just in case.
507       ASSERT_NE(ptr, ptr2);
508       _aligned_free(ptr);
509       _aligned_free(ptr2);
510     }
511   }
512 }
513 
514 #endif
515 
516 
main(int argc,char ** argv)517 int main(int argc, char** argv) {
518   testing::InitGoogleTest(&argc, argv);
519   return RUN_ALL_TESTS();
520 }
521